Table 1.

The X-ray score of the four groups at different time

	2 weeks	4 weeks	8 weeks	12 weeks	24-week
Group A	0 ± 0	0 ± 0	0 ± 0	0 ± 0	0 ± 0
Group B	0 ± 0	2.33 ± 1.54	6.33 ± 0.58*	7.33 ± 1.53	10.33 ± 1.53
Group C	0 ± 0	2.00 ± 1.00	3.67 ± 0.58*	5.00 ± 1.00*	5.33 ± 1.53*
Group D	0 ± 0	2.33 ± 0.58	4.00 ± 1.00#	6.33 ± 0.58	8.67 ± 1.12□
F	–	0.125	11.400	3.364	9.722
P value	–	0.885	< 0.05	0.105	< 0.05

Data are expressed as mean ± standard deviation. There was no difference in the 2nd week for each group, which was not included in the statistical category. Group A had no difference in each time point and was not included in the statistical category. *P value < 0.05, group C compared with group B. ^#P value < 0.05, group D compared with group B. □P value < 0.05, group C compared with group D